1. Field of the Invention
The present invention relates to toy balloons and, more specifically, to a lighter-than-air, non-rigid, rubber band powered toy balloon using a propeller or a flapping vane for propulsion.
2. Art Background
Toy balloons have entertained youngsters and adults alike for many years. They have come in various shapes and sizes and have been filled with air, helium or even water.
Air filled toy balloons are often used for decorative purposes, or are repeatedly bounced or hit into the air for play. Because air filled balloons are heavier than air, however, they do not remain aloft very long.
Helium-filled balloons, on the other hand, are lighter than air and therefore tend to rise aloft. Hand held tethers are usually required to prevent helium-filled balloons to rising too far. If a helium-filled balloon is released indoors, it will rise up to the ceiling. If released outdoors, it will rise up to its buoyant height, which is the height at which the weight of the air displaced by the balloon (which decreases with increasing altitude) exactly equals the balloon weight. Conventional helium-filled toy balloons usually have buoyant heights of several hundred feet.
The buoyant height of a helium-filled balloon can be changed by altering the weight of the balloon, its helium content or both. At least one prior art design uses removable weights that can be affixed to the outside surface of the balloon to change the balloon's weight, while another adds weights to a container suspended below the balloon. By adjusting the weight of the balloon in sufficiently small increments, it is possible to adjust the buoyant height within a range of about 5 to 10 feet.
To add horizontal movement to a balloon's behavior, several prior art designs have outfitted balloons with rubber band powered propeller mechanisms. In the prior art, such mechanisms have included a rubber band, a propeller, and a support frame or spine for resisting the tension of a fully wound rubber band. The support frame may be disposed within, attached to the outside, or suspended beneath the balloon. Single or double propellers have been used.